Lower GI Anatomy

Question 1

small intestine sections (4)

Answer 1

20ft coiled tube

1. duodenum
2. jejunum
3. ileum
4. ileocecal valve

Question 2

structures of small intestinal wall

Answer 2

1. circular folds (increase surface area of mucous membrane)
2. villi (small finger like projections on circular folds)
3. microvilli (smaller projections on the villi)

Question 3

pyloric sphincter

Answer 3

connection btwn stomach and small intestine

releases stomach contents (chyme) into pyloric sphincter

Question 4

large intestine sections (8)

Answer 4

1. cecum
2. appendix
3. ascending colon
4. transverse colon
5. descending colon
6. sigmoid colon
7. rectum
8. anal canal

Question 5

cecum

Answer 5

entrance to large intestine, appendix is attached

Question 6

ascending colon

Answer 6

runs superiorly along right side of abdomen

Question 7

transverse colon

Answer 7

connects to ascending colon via right colic (hepatic) flexure, runs across the abdomen

Question 8

descending colon

Answer 8

connects to transverse colon via left colic (splenic) flexure, runs along left side of abdomen

Question 9

sigmoid colon

Answer 9

travels through pelvis, connects with rectum

Question 10

rectum

Answer 10

last 20cm of large intestine that connects to anal canal

Question 11

anal canal

Answer 11

end of gi tract
where feces expelled via anus
internal sphincter (involuntary smooth muscle) & external sphincter (voluntary skeletal muscle) control defecation

Question 12

appendix

Answer 12

hangs from cecum, if bacteria accumulates –> inflamed

–> appendicitis

Question 13

feces

Answer 13

75% water, 25% solid matter (1/3 of which = intestinal bacteria, other materials = undigested plant material, fats, waste products, inorganic material, mucus, dead intestinal lining cells